Explanation:
Yes you find the area of a rectangle (and square) by multiplying length X width. For shape A. it would be 7 3/4 ft. times 10 1/5 ft. For B. it would be 12.3 mi times 12.3 mi. You can put that in the calculator and get the answer.
For shapes C. and D, the area formula is a little different. For C. it would be done by multiplying base X height. So 4 2/3 cm times 3 3/8 cm. For D. the area formula would be 1/2 X base X height. So i think you do 67 cm times 79.2 cm AND THEN divide that answer by 2.
SO AREAS ARE:
A. 79 1/20 ft^2
B. 151.29 mi^2
C. 15 3/4 cm^2
D. 2653.2 cm^2
For perimeter, its pretty straight forward. You just have to add all of the sides lengths together. SO PERMITERS ARE:
A. 7 3/4 + 7 3/4 + 10 1/5 +10 1/5 = 35 9/10 ft.
B. 12.3 + 12.3 + 12.3 + 12.3 (or 12.3 times 4 to be quicker)= 49.2 mi
C. 3 5/6 + 3 5/6 + 4 2/3 + 4 2/3= 17 cm
D. 67 + 85.32 + 126.75= 279.07 cm